1. Field of the Invention
The present invention relates to a method for fabricating a capacitor of a semiconductor device, and more particularly to a method for fabricating a capacitor of a semiconductor device capable of forming a cylinder without etching back storage node polysilicon, in order to easily grow MPS (Meta Poly silicon)-affected by a carbon component generated through a storage node polysilicon etch back process, which is performed for forming a cylinder capacity using the storage node polysilicon.
2. Description of the Prior Art
Hereinafter, a conventional method for fabricating a capacitor of a semiconductor device will be briefly described.
FIGS. 1a to 1f are sectional views showing the conventional method for fabricating the capacitor of the semiconductor device.
As shown in FIG. 1a, according to the conventional method for fabricating the capacitor of the semiconductor device, a first insulating interlayer 11 is selectively removed by using a plug contact mask (not shown) after initially depositing the first insulating interlayer 11 on a semiconductor substrate (not shown), thereby forming a plug contact hole (not shown).
Subsequently, after depositing a conductive material layer on the first insulating interlayer 11 including the plug contact hole (not shown), a contact plug 13 is formed in the plug contact hole (not shown) through a total etching process or a CMP (Chemically and Mechanically Polishing) process.
Next, after a second insulating interlayer 15 is deposited on the first insulating interlayer 11 including the contact plug 13, a resist pattern (not shown) is formed on the second insulating interlayer 15 in order to use the resist pattern as a storage node contact mask.
Subsequently, the second insulating interlayer 15 is removed by using the resist pattern (not shown) as a mask, thereby forming a storage contact hole 17.
Thereafter, as shown in FIG. 1b, after removing the resist pattern (not shown), a polysilicon layer 19 for the storage node is deposited on the second insulating interlayer 15 including the storage node contact hole 17. The polysilicon layer 19 is a cylinder layer used as the capacitor.
Next, as shown in FIG. 1c, a photo-sensitive material film 21 is coated on the polysilicon layer 19, thereby filling the storage node contact hole 17 with the photo-sensitive material.
Subsequently, as shown in FIG. 1d, the photo-sensitive material film 21 and the polysilicon layer 19 are selectively removed through the total etching process or the CMP process. At this time, an upper surface of the second insulating interlayer 15 acts as an etch stop point. In this case, the photo-sensitive material film 21 is required remaining only in the storage node contact hole 17.
Subsequently, as shown in FIG. 1e, a photo-sensitive material film 21a remaining in the storage node contact hole 17 is removed.
Next, as shown in FIG. 1f, an MPS layer 23 is grown on a surface of the polysilicon layer 19a. 
Subsequently, a dielectric layer (not shown) and an upper electrode (not shown) are sequentially formed on the polysilicon layer 19a including the MPS layer 23, thereby fabricating the capacitor.
However, according to the conventional method for fabricating the capacitor, a carbon component or the likes generated through an etch back process for the polysilicon layer 19a may affect an influence on an MPS growth, which exerts an influence on the capacitance value.
FIG. 2 shows a case in which MPS is abnormally grown due to reasons described above. FIG. 3 shows a result of an etch-back effect in the storage node polysilicon layer, which is achieved by growing MPS after depositing storage node polysilicon without performing the etch back process.
Accordingly, it is understood from FIGS. 2 and 3 that a degree of the MPS growth is varied depending on the etch back process for the storage node polysilicon. In other words, the etch back process for the storage node polysilicon layer, which is performed in order to insulate between cylinders, may interfere the MPS growth. For this reason, the performance of the capacitor is degraded.